Chemical Sciences: A means of fingerprinting explosives

A method to detect tiny amounts of explosives, while simultaneously giving information on the nature of the explosive material, is reported this week in Nature Communications.

Often detectors only work for a small number of explosive species, but the range of potential threats is very broad. Additionally, the ability to detect low levels of these chemicals is vital-many explosives have low volatility, so only trace amounts will be present in the air.

Fernando Patolsky and colleagues showed that their system was not specific for just one type of explosive. Each explosive interacts slightly differently with the sensor, giving a distinct pattern that the researchers could use to build a unique “fingerprint”. Such “fingerprinted” explosives can then be easily identified in the future, allowing TNT and other common explosives to be detected and identified at parts-per-quadrillion concentration levels.

One further advance is the ability to detect peroxide based explosives. These raise security concerns due to the ease with which they can be made, starting from household materials, and have proven difficult to detect with high sensitivity. This technique allows for their detection and discrimination from more innocent, but chemically related, species.